No worries here, there are lots of theory's out there on this. I'm curious how you'd possibly have data on this though as you'd have to have two identical manifolds with nothing different but runner diameter.

LeMans and CART disagree though as most teams use(d) stepped runners in their manifolds. They actually use the cross section change to produce resonant tuning peaks.

 

no space, and the sump would be in the way too..

 

http://www.pipeflow.com/public/image...or_chart_1.gif

Investment casting is in the 0.000050" to 0.000200" range and cold rolled steel is in the 0.000025" to 0.000100" range. How it ends up after bending I couldn't say.

Relative roughness though, 0.000200"/1.55" = 0.00013 -> friction factor of 0.020
0.000025"/1.55" = 0.000016 -> friction factor of 0.014

As you can see, it's no where close to 8x higher here. Surface finish is almost irrelevant when talking about the materials typically used for manifolds.

Compared to http://www.thermopedia.com/content/5...FAPDI)Fig3.gif

Double the bend radius ratio from 1 to 2 on the other hand and it cuts losses in half. Or for a different perspective, a 90* bend on a 1:1 bend ratio has close to the same losses as a 180* bend on a 1.5:1 bend ratio.

 

Tuned one of the new FullRace 7163 low mount IWG kits earlier in the week.
Very impressed with spool and transient!

Setup was:
Stock block/stock cams Evo 9,
Magnus V5 plenum,
Boomba 70mm t/b,
HKS cooler
STM 3inch SD intake with bellmouth filter.
98RON fuel (~92MON)

Car still an ongoing operation atm as there are boost control issues, however on the street, starting at 2500rpm, I am seeing gate pressure (~14psi) by ~3300rpm in 3rd.

 

TS or SS?

 

full race IWG kit is T4 - TS..

i am impressed with that spool treshold..

 

hi , 3300rpm 3rd gear is nice, for stock engine stock cams. what is the boost control issue? we will tune my friend Ramon evo at Evans Tuning soon, evo8, 7163 fullrace. we use the turbosmart iwg on this one

 

Please post some dyno results.

 

+1

 

I'll post results once finished.
Have you fitted the TS gate yet? I suspect it may require spacing as the FR gate is very close to the gearbox/block on the inside of the kit.

Turbo won't make dramatic boost increases, I wonder if the gate is being blown open.
Customer added tension to the rod and boost rose accordingly.

 

Any results yet? Shouldn't take long to track down a boost leak.

 

On my 7163 I found that the stock WG actuator mounting bracket is making the actuator sit at a wrong angle. I will go to a longer rod actuator and mount it at a better angle, for more force on the flapper and better fittment with regards to the block..

 

you are certain this isnt simply a clocking issue? the options arent limitless for alignment on them- they have to be clocked accordingly-

cb

 

Every time I see that CBRD has a new post in this thread I get excited expecting to see some 7163 4g63 dyno results. Why so cruel? We need data

 

the EWG has a stamped carrier that is at an angle and since the rod has just a few deg of freedom there is only one way ofplacing the EWG in relation to exhaust housing



this makes the rod come in to the flapper arm at an angle of 64 deg, instead of 90 deg. Ok, it is not a huge difference, the force is about 11% lower because of that, but still.



Also, the EWG actuator fouls the block, in my application, so I will reposition it so that it sits closer to the turbo body and that the rod goes in at 90 deg angle. This way it will not hit the block. I need the long rod actuator for that, so the longest turbosmart will do. I am still thinking of getting the twin port one.. just in case.. I can always run stiff spring in that one and use it as single port..